Fix issue related to saving customers

[snoop0x7b]

Context

This pull request fixes issue #375

Description

This fixes the bug in issue #375

Performance

No impact on performance - It adds null checks.

Testing

You can test this by replicating the issue in #375 and then applying this patch and seeing if it still causes the issue. After doing these changes, we stopped having that particular issue and were again able to save customer accounts as expected.

Versions

• [X] Magento 2.4
• [ ] Magento 2.3
• [ ] Magento Open Source (formerly Magento 2 Community Edition)
• [X] Adobe Commerce (formerly Magento 2 Enterprise Edition)
• [X] PHP 8.2
• [ ] PHP 8.1
• [ ] PHP 7.4
• [ ] PHP 7.3

[CLAassistant]

All committers have signed the CLA.

[snoop0x7b]

Hey Taxjar team

Any plans to merge this PR? Your extension may not work correctly with supported versions of Magento without this update. We're currently relying on a patch I created in our project.